In U.S. Pat. No. 5,017,432 to Eddy et al., commonly assigned to the assignee of the present application, a fuser member and fuser system are described wherein a polymeric release agent having functional groups is supplied to the surface of a fuser member which comprises a poly(vinylidenefluoride-hexafluoropropylene-tetrafluoroethylene) wherein the vinylidenefluoride is present in an amount less than 40 mole percent, a metal oxide is present in amount sufficient to interact with the polymeric release agent having functional groups to provide an interfacial barrier layer between fusing surface and the toner is substantially unreactive with the elastomer and wherein the elastomer is cured from a solvent solution thereof with a nucleophilic curing agent soluble in the solution and in the presence of less than 4 parts by weight of inorganic base per 100 parts by weight of polymer with the inorganic base being effective to at least partially dehydrofluorinate the vinylidenefluoride. U.S. Pat. No. 5,017,432 together with those patents described in the prior art section of that patent disclosure are hereby specifically and totally incorporated by reference into the instant specification. In the practice of the fuser member described in U.S. Pat. No. 5,017,432, at least one elastomeric layer is positioned between the base member and the outer layer and is typically also a poly(vinylidenefluoride-hexafluoropropylene-tetrafluoroethylene) wherein the vinylidenefluoride is present in an amount less than 40 mole percent, which is adhesively bound to an aluminum coated copper base in some instances and to an all aluminum base in other cases by an epoxy adhesive such as Thixon 300/301. Thixon is a trademark of Dayton Chemical Products Laboratories. While such a fuser member provides a relatively long life on the average having a copy count of 1.9 to 2.1 million copies for all failure modes in the Xerox 5090 printing machine, it does suffer a particular failure of the fluoroelastomer fusing surface debonding from the aluminum substrate. It has been determined that the bond between the aluminum surface and the fluoroelastomer fusing layer degrades as a function of time at the elevated temperatures involved in the fusing process which may exceed 400.degree. F. The Thixon epoxy adhesive degrades to the point where it no longer functions as an adhesive and failure is experienced with wholesale debonding of the fusing layer from the aluminum substrate in that the fusing surface may be manually peeled from the aluminum substrate.
In U.S. Pat. No. 5,049,444 to Bingham et al., entitled "Silane Adhesive System For Fusing Member" and commonly assigned to the assignee of the present application, an adhesive layer includes a copolymer of vinylidenefluoride and hexafluoropropylene and at least 20 percent by weight of a coupling agent which comprises at least one organofunctional silane and an activator. In a specific embodiment, the organofunctional silane is a mixture of about 4 parts by weight of ethenyl triethoxy silane to one part by weight of 3-(triethoxy silyl)-1-propanamine such as that available from Minnesota Mining and Manufacturing Company under the designation Dynamar 5150. This is a 6 percent mixture of the active ingredients and benzyl triphenyl phosphonium chloride curing activator in 94 percent methanol with a small amount of water. While this organofunctional silane coupling agent, when mixed with a copolymer of vinylidenefluoride and hexafluoropropylene having a relatively low molecular weight, provides a good adhesive between the base support member and the tie coat layer or elastomeric fusing surface, it is inadequate when used with the higher molecular weight fluoroelastomers such as Viton GF, a polymer of 35 mole percent vinylidenefluoride, 34 mole percent hexafluoropropylene and 29 mole percent tetrafluoroethylene. This is believed to be due to the fact that the organofunctional silane coupling agent and high molecular weight fluoroelastomer do not evenly coat the aluminum substrate, but rather provide a discontinuous (less than 50 percent of the surface is covered) layer on the aluminum substrate. This is believed to be due to the highly polar nature of the water and the alcohol which cause the relatively high molecular weight Viton GF to come out of solution, even forming clumps of the fluoropolymer and not uniformly coating the substrate.